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arXiv · 0811.3813

Anomalous isotope effects of fulleride superconductors

W. Fan
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Abstract

The numerical calculations of the standard Eliashberg-Nambu strong coupling theory and a formula of isotope effect derived in this paper provide direct evidences that an-harmonic vibrations of lattice enhance isotope effect with anomalous coefficient $α>1/2$. The results in this paper explain very well the wide distributed $α$ values for the samples with different ratios of substitutions of $^{12}$C by $^{13}$C of fulleride superconductor Rb$_{3}$C$_{60}$. The calculations of isotope effects indicate that the intra-molecule radial modes have more important contributions to superconductivity than the intra-molecule tangential modes with higher phonon frequencies

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W. Fan. 2008-11-24. Anomalous isotope effects of fulleride superconductors. https://arxiv.org/abs/0811.3813

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